摘要:

Observations in Worcestershire have shown that heavy losses of salad onions due to white rot may occur on sites which have not been known to carry a previous susceptible crop. Reasons for this are discussed. During five seasons a good control of the disease has been obtained by treating the seed with pure calomel applied with a resin‐alcohol sticker. The treatment also gave some control of damping off of seedlings due toCorticium solani.Broadcasting 4 % calomel dust at 2½‐3 cwt. per acre was less satisfactory in controlling white rot. In one season promising results were obtained with seed treatment of bulb on

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02374.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

摘要:

In field trials near Evesham, Worcestershire, a good control of onion smut was obtained by seed treatment with ferbam and 50 % thiram dusts applied with a resin‐potash sticker. A pentachloronitrobenzene compound also gave some control of the disease but reduced emergence. Greenhouse trials confirmed these results, but there was a fall off in control at high levels of infection. Chloranil and calomel were relatively ineffective and two organo mercury compounds caused serious seed injur

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02375.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

摘要:

Three clones ofVenturia pirinahave been tested for their pathogenicity towards forty varieties of cultivated pear. From observations on the reactions of these forty varieties, twelve were selected for differentiating the pathogenicity of sixteen clones of the fungus.These tests differentiated four main groups of biotypes ofV. pirina.Clones isolated from Conference showed wide differences in range of pathogenicity. One isolate from Conference was shown to parasitize six of the most widely grown pears in England: other Conference biotypes had a narrow range.No variety of pear was found immune to all the isolates. Beurré Giffard was lightly infected by an isolate from Durondeau, but was resistant to all the other isolates tested

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02376.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

摘要:

Clonal isolates ofVenturia pinna, shown in a previous paper to differ in range of pathogenicity, have been used to inoculate the following pear seedlings: (i) resistant seedlings from families which appeared to be segregating for resistance under field conditions, (ii) two whole families of field‐resistant × field‐susceptible parentage.In (i), it was found that clones of the fungus could infect some of the seedlings hitherto regarded as field‐resistant. In (ii), segregation for susceptibility in the two families varied, according to the clone of the fungus used, from approximately a 1:1 ratio down to ‘all resistant’. Resistance to individual clones appeared to be dominant to susceptibility, but further data are required before attempting a complete interpretation.There was a general correlation between susceptibility to the different clones. Those that produced the most infection were isolated from the parental varieties of the seedlings. This correlation was not, however, complete and clones differing in host origin tended to attack different groups of

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02377.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

摘要:

Wounds were made at various times of the year on the trunks and large branches of apple trees with a 1 in. bit and treated with a number of organic compounds in lanoline paste. The healing of these wounds was followed through two growing seasons by tracing and measuring the area of exposed wood at different times after wounding.Callus growth was practically confined to the summer months. Development of callus was improved by applications of lanoline, and the lanoline effect could be further enhanced in the early part of the first growing season following treatment by the addition of certain growth‐stimulating compounds including 4‐chloro‐3:5‐dimethylphenoxyacetic acid and 2:4‐dichlorophenoxyacetic acid. Indolyl‐3‐butyric acid probably also caused some stimulation. After the period of initial stimulation the rate of callusing was approximately the same on treated as on unt

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02378.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

摘要:

Autumn injections of D‐D mixture have been annually repeated for three years on a silt soil at Moulton (Holland, Lincolnshire) and a black fen soil at Prickwillow (Ely, Cambridgeshire), with different results. At Moulton there was an increased yield of tubers each time D‐D was used, with no significant residual effects after the first year, and no marked long‐term effect on the eelworm population. At Prick‐willow D‐D gave an increased yield in the first season only, with no positive residual effects on yield, and an apparent stimulating effect on the eelworm population. At Moulton in 1948 and 1950 (butnotin 1949) the cost of the D‐D treatment was heavily outweighed by the value of the resultant increase in crop. However, on the organic soil at Prickwillow D‐D treatment was ineffective in 1949 and 1950 and the eelworm population, initially higher than at Moulton, remained at a level inducing failure of the

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02379.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02380.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02381.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02382.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1953.tb02383.x

出版商:Blackwell Publishing Ltd    

年代:1953

数据来源: WILEY